U.S. patent number 4,140,280 [Application Number 05/734,731] was granted by the patent office on 1979-02-20 for portable hand-held, manually-operated duster.
This patent grant is currently assigned to Bermuda Research Corp.. Invention is credited to Francis F. Allen, James C. Nichol.
United States Patent |
4,140,280 |
Allen , et al. |
February 20, 1979 |
Portable hand-held, manually-operated duster
Abstract
A hand-held, manually-operated duster for propelling a
controlled stream of pulverulent material, such as an insecticide
dust, onto vegetables, roses, flowers, shrubs and small trees and
the like and which comprises a unitary housing providing a material
hopper and separate impeller and drive chambers, a rotary impeller
being mounted in the impeller chamber and a hand crank and gear
train being mounted in or associated with the drive chamber and
connected to the impeller, powder being fed from the hopper to the
impeller for discharge in a controlled stream.
Inventors: |
Allen; Francis F. (Lakeview,
OR), Nichol; James C. (Orinda, CA) |
Assignee: |
Bermuda Research Corp. (San
Francisco, CA)
|
Family
ID: |
24952866 |
Appl.
No.: |
05/734,731 |
Filed: |
October 22, 1976 |
Current U.S.
Class: |
239/654;
74/606A |
Current CPC
Class: |
A01C
15/02 (20130101); A01M 9/0038 (20130101); Y10T
74/2189 (20150115) |
Current International
Class: |
A01M
9/00 (20060101); A01C 15/02 (20060101); A01C
15/00 (20060101); A01C 015/02 () |
Field of
Search: |
;239/654 ;222/193
;74/66R,66A ;308/DIG.7,DIG.8 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Love; John J.
Assistant Examiner: Forman; Michael J.
Attorney, Agent or Firm: Warren, Chickering &
Grunewald
Claims
What is claimed is:
1. A portable hand-held manually operated duster for propelling a
controlled stream of pulverulent material comprising:
a housing providing a material hopper and impeller and drive
chambers, said impeller and drive chambers being positioned in
substantially vertical planes in the normal position of use of the
duster;
said housing providing an interior wall for said drive chamber
having a normal position of use in a substantially vertical
plane;
a side-mounted, vertically disposed closure plate for said drive
chamber;
a manually engageable crank having a shaft journalled for rotation
on said plate;
a gear train in said drive chamber connected to said crank and
composed of a plurality of molded plastic enmeshed speed
multiplication gears and terminating in a high speed driven gear
disposed at the normally lower end of said gear train and including
a pair of intermediate gears connected for joint rotation about a
common axis, one of said intermediate gears being enmeshed with and
driving said high speed driven gear;
said interior wall and plate providing bearings on said axis;
a metallic shaft supporting said intermediate gears and journalled
in said bearings;
an impeller mounted for rotation in said impeller chamber;
a molded plastic shaft supporting and fixed for rotation with said
high speed gear and extending through said interior wall and
connected to said impeller;
said plate providing a bearing supporting one end of said
last-named shaft;
a Teflon bearing mounted in said interior wall and journalling said
last-named shaft; and
said housing being formed with an air inlet opening adjacent the
base of said drive chamber; and
said plate being formed with a bearing journalling said crank shaft
at the normally upper end of said gear train, said plate being
formed with a plurality of discharge openings disposed in
circumferentially spaced relation around said bearing adjacent the
upper end of said drive chamber and providing air discharge
passages extending from said drive chamber to the atmosphere for
inducing a flow of air cooling said gear train and freeing said
drive chamber from pulverulent material entering therein.
2. The apparatus of claim 1, said housing having a second
vertically disposed interior wall defining in part said impeller
chamber, said second wall being formed with an integral laterally
extending peripheral wall;
said impeller having a hub and a plurality of radial vanes with
said hub mounted on said plastic shaft for rotation therewith in a
substantially vertical plane in position of use;
a second side-mounted vertically disposed plate mounted on said
peripheral wall and enclosing said impeller chamber and having a
lateral wall surrounding said impeller vanes and extending
substantially to said second interior wall and providing a squirrel
cage chamber around said impeller, said lateral wall having a
discharge passage for pulverulent material driven by said
impeller;
said peripheral wall having an opening therein in the normally
lower end thereof to prevent the accumulation of material bridging
a lower section of said squirrel cage chamber; and
an abrasion-resistant bearing mounted on said second plate and
journalling the opposite end of said plastic shaft.
Description
BACKGROUND OF THE INVENTION
The invention relates to apparatus used by gardeners and,
particularly, home gardeners, and commonly referred to as dusters
for spraying of insecticidal garden dust or powders onto growing
plants, bushes, shrubs and the like. The present application
presents specific improvements on a hand duster disclosed in U.S.
Pat. No. 3,330,445.
It has been proposed, see U.S. Pat. No. 3,330,445, to combine in a
lightweight, portable, hand-operated duster a material hopper for
the pulverulent material, a high-speed rotary impeller for
propelling the material in a controlled stream for dusting plants
and the like, and a manually-operated crank and gear train
connected to the impeller for generating the required high-speed
rotation thereof. One of the problems encountered is overheating
and deterioration of certain high-speed parts. Another problem
encountered is that the garden dusts are exceedingly fine and will
penetrate and infiltrate bearings, gears and other moving parts and
are, at the same time, highly abrasive and, accordingly, abrade and
destroy critical moving parts and cause early and premature failure
of the structure. Also, certain garden dusts absorb moisture and
harden. An uncontrolled build-up of such material in the impeller
chamber may break up the impeller.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a portable,
hand-held, manually-operated duster of the character described
which is self-ventilating and constantly self-cleaning in those
sensitive areas affected by the uncontrollable entry of the garden
dust being used, and which will function to constantly move out
dust entering critical operational areas, with the result that the
high-speed parts are protected from the deleterious accumulation of
the abrasive and self-hardening action of the garden dust being
dispersed.
Another object of the present invention is to provide a garden
duster of the character described having improved bearing
structures for certain of the sensitive high-speed moving parts,
thereby obtaining a heretofore not attainable dependability and
satisfactory long life for the apparatus.
The invention possesses other objects and features of advantage,
some of which of the foregoing will be set forth in the following
description of the preferred form of the invention which is
illustrated in the drawings accompanying and forming part of this
specification. It is to be understood, however, that variations in
the showing made by the said drawings and description may be
adopted within the scope of the invention as set forth in the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a portable, hand-held,
manually-operated duster constructed in accordance with the present
invention.
FIG. 2 is a fragmentary side elevation of the duster with a side
plate removed.
FIG. 3 is a side elevation of the side plate removed in the showing
of FIG. 2.
FIG. 4 is a cross-sectional view on an enlarged scale taken
substantially on the plane of line 4--4 of FIG. 1.
FIG. 5 is a fragmentary cross-sectional view on a further enlarged
scale of a portion of the mechanism illustrated in FIG. 4.
FIG. 6 is an opposite side elevation of the device with the
opposite side plate removed.
FIG. 7 is a side elevation of the side plate removed in the showing
of FIG. 6.
FIG. 8 is a cross-sectional view on an enlarged scale taken
substantially on the plane of line 8--8 of FIG. 6.
FIG. 9 is a fragmentary cross-sectional view on a further enlarged
scale of a portion of the structure shown in FIG. 8.
DETAILED DESCRIPTION OF INVENTION
The duster of the present invention comprises, briefly, a housing
11 providing a material hopper 12 and impeller and drive chambers
13 and 14, here positioned on opposite sides of hopper 12; a
closure plate 16 for drive chamber 14; a manually engageable crank
17, journalled for rotation on plate 16; a gear train 18 in drive
chamber 14 connected to crank 17; one of the improvements of the
present invention comprising vent openings 21 and 22 formed in the
base and side of the drive chamber for circulating cool air through
the drive chamber and freeing it from pulverulent material entering
therein. As will be best seen from FIG. 4, plate 16 is formed with
a bearing opening 23, for the shaft 24 of crank 17, and the side
vent 22 for the chamber is provided by a plurality of
circumferentially spaced openings 22 surrounding bearing 23, see
FIGS. 1 and 3.
As will also best be seen in FIG. 4, housing 11 is formed with an
interior wall 26 defining one side of hopper 12 and the interior
side of drive chamber 14, and which is normally positioned in a
substantially vertical plane in the operation of the duster, and an
integral annular, laterally-extending peripheral wall 27
surrounding the drive chamber and against which closure plate 16 is
mounted to enclose the chamber; and opening 21 is here formed in
the normally bottom side 28 of peripheral wall 27 at the bottom of
drive chamber 14. Accordingly, any of the garden dust finding its
way into the drive chamber from hopper 12 may gravitate out of
opening 21. Moreover, in the operation of the device, the whirling
action of the gear train establishes an air current or flow through
the chamber by way of openings 21 and 22 so as to constantly
establish a stream of cooling air through the drive chamber and to
move out any dust entering this critical operational area.
The function of gear train 18 is to convert a comfortably fast
rotation of crank 17 into a high-speed rotation of impeller 31,
positioned in chamber 13. This is here accomplished by a shaft 32,
which connects the small terminal high-speed driven gear 33 of the
gear train with the hub 34 of impeller 31, shaft 32 here extending
between chambers 13 and 14 straight across the bottom of the hopper
12. Vanes 36 are formed on shaft 32 in the hopper chamber for
transporting the garden dust laterally through an opening 37
surrounding shaft 32 in an interior wall 38 dividing the hopper
compartment from impeller chamber 13 so as to deliver the garden
dust to the eye of impeller 31. As a feature of the present
construction, the major portions of the duster, including housing
11, a lid 39 capping the hopper compartment 12, crank 17, shafts 24
and 32, and all of the gears making up the gear train, are formed
of plastic materials selected to provide necessary strength,
anti-corrosion qualities, and being capable of injection molding.
The critical working parts, including the gears, shafts and
impellers, are preferably constructed of a composite plastic
comprising glass-filled nylon (about 10% glass fiber) and about 5%
polytetrafluoroethylene commonly sold under the trademark Teflon.
The housing and associated nonworking parts may be formed of
polypropylene. One of the critical areas is the proper support of
shaft 32 and its attached gear 33 for the stresses and high-speed
operation to which these parts are subjected. It has been found
that the required strength, durability, and low-friction support
for shaft 32 may be obtained by journalling the shaft in a Teflon
bearing 41 mounted in interior wall 26, see FIGS. 4 and 5.
Another and important structural improvement of the present
invention is the support provided for a pair of intermediate gears
42 and 43, which are preferably molded as a one-piece construction
and, in any event, connected for joint rotation on a common shaft
44, gear 43 being enmeshed with and driving gear 33, and gear 32
being enmeshed with and driven by gear 46, carried by crank shaft
24. As here best seen in FIG. 4, shaft 44 is made of brass and is
carried at its opposite ends in bearings 47 and 48, formed in
confronting relation on plate 16 and interior wall 26. The
journalling of brass shaft 44 in plastic bearings 47 and 48
provides an important improvement in strength, wear resistance,
precision of operation, and low friction.
The internal end of crank shaft 24 is preferably carried through
wall 26, see FIG. 4, and is connected to the hub 51 of a
dust-stirring member 52, which is rotated by the crank within
hopper chamber 12 for keeping the powder in a loose, flowable
condition, it being noted from FIG. 8 that the opposite end 53 of
member 52 is journalled for rotation in an opening provided in
interior wall 38 at the opposite side of the hopper chamber.
Another feature of the present invention is the provision of an
improved support for the impeller 31 and means to prevent the
accumulation and build-up of dust in the impeller chamber. Although
it is recommended that the apparatus be washed with water after
each use so as to flush out dust, a failure to do so in the past
has permitted a build-up of dust in the impeller chamber. Many
types of dust will absorb water and harden. A solid bridge may thus
form across the bottom of the impeller chamber which will impact
and break the impeller blades or vanes 56, with the resultant
failure of the device.
With reference to FIGS. 6-8, it will be noted that interior wall 38
partitioning the hopper and impeller chambers is formed with an
integral, laterally-extending, peripheral wall 57, and a plate 58
is mounted on wall 57 to enclose the impeller chamber and is, in
turn, formed with a lateral wall 59 surrounding vanes 56 and
providing a squirrel cage chamber 61 therefor, having a discharge
passage 62 for the garden dust driven by the impeller. As an
important feature of the present construction, peripheral wall 57
is formed with an opening 63 in the normally lower end 64 thereof,
which effectively prevents the accumulation of material within and
bridging the lower section of the squirrel cage chamber. Plate 58
also provides an outboard bearing for shaft 32 and is formed with a
plurality of circumferentially spaced openings 66 surrounding the
axis of shaft 32 for admitting air into the impeller chamber at the
base of vanes 56 for aerating the garden dust drawn through opening
37 and for admixing with and transporting the dust out of discharge
opening 62.
The outboard bearing for shaft 32 has been another critical
structural area causing premature failure of the present device.
This problem has been solved by using a brass bearing 67 for the
cylindrical outboard end 68 of shaft 32. As here shown, bearing 67
comprises a brass sleeve, which is carried in a surrounding
shoulder 69 formed on plate 58 and which positions the bearing in
axial alignment with shaft 32 for receiving and journalling shaft
end 68.
Closure plates 16 and 58 may be secured in place by screws 71
threaded into bosses 72 formed on interior walls 26 and 38. A
handle 77 is mounted on the normally rear wall 73 of housing 11 for
convenient manual support in one hand of the user while the other
hand is engaged with crank 17. A fitting 74 is mounted at the
normally forward side 76 of housing 11 for receipt of one or more
spray extension tubes (not shown).
* * * * *